Nicolai Ouroussoff may think Renzo Piano’s addition to the Morgan Library and Museum is “dazzling,” but from the outside it looks to me like the shop class entrance of a prefab suburban high school. Like temporary shelter thrown down by the only bidder to make it through onerous bureaucratic paperwork. What kind of ego takes one of the last brownstones left on Madison Avenue and glue-guns up two storeys of barn siding right next to it? Mere feet away?